None of the architecture on Euro banknotes is real, as the EU prohibited displaying any national monuments, so to not give greater prominence to one country over another. Hence, for the €5 note, a computer was used to scan multiple European bridges and combine them into one neutral design.
During WWII, Hawaii had its own unique US banknotes. In case of Japanese invasion, the US government would have declared the notes worthless to prevent their use by Japanese troops.
The Canadian $100 banknote featured an Asian woman on the back using a microscope. People complained that it was stereotyping Asians as being good at technology. She was replaced with a Caucasian woman, and then more people complained that Caucasians were being favored.